/* Copyright (c) 2010, Carl Burch. License information is located in the
 * com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */

package com.cburch.logisim.circuit;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;

import com.cburch.logisim.comp.Component;
import com.cburch.logisim.data.Attribute;
import com.cburch.logisim.data.AttributeSet;

class CircuitMutatorImpl implements CircuitMutator {
    private ArrayList<CircuitChange> log;
    private HashMap<Circuit,ReplacementMap> replacements;
    private HashSet<Circuit> modified;

    public CircuitMutatorImpl() {
        log = new ArrayList<CircuitChange>();
        replacements = new HashMap<Circuit,ReplacementMap>();
        modified = new HashSet<Circuit>();
    }

    @Override
    public void clear(Circuit circuit) {
        HashSet<Component> comps = new HashSet<Component>(circuit.getNonWires());
        comps.addAll(circuit.getWires());
        if (!comps.isEmpty()) {
            modified.add(circuit);
        }

        log.add(CircuitChange.clear(circuit, comps));

        ReplacementMap repl = new ReplacementMap();
        for (Component comp : comps) repl.remove(comp);
        getMap(circuit).append(repl);

        circuit.mutatorClear();
    }

    @Override
    public void add(Circuit circuit, Component comp) {
        modified.add(circuit);
        log.add(CircuitChange.add(circuit, comp));

        ReplacementMap repl = new ReplacementMap();
        repl.add(comp);
        getMap(circuit).append(repl);

        circuit.mutatorAdd(comp);
    }

    @Override
    public void remove(Circuit circuit, Component comp) {
        if (circuit.contains(comp)) {
            modified.add(circuit);
            log.add(CircuitChange.remove(circuit, comp));

            ReplacementMap repl = new ReplacementMap();
            repl.remove(comp);
            getMap(circuit).append(repl);

            circuit.mutatorRemove(comp);
        }
    }

    @Override
    public void replace(Circuit circuit, Component prev, Component next) {
        replace(circuit, new ReplacementMap(prev, next));
    }

    @Override
    public void replace(Circuit circuit, ReplacementMap repl) {
        if (!repl.isEmpty()) {
            modified.add(circuit);
            log.add(CircuitChange.replace(circuit, repl));

            repl.freeze();
            getMap(circuit).append(repl);

            for (Component c : repl.getRemovals()) {
                circuit.mutatorRemove(c);
            }
            for (Component c : repl.getAdditions()) {
                circuit.mutatorAdd(c);
            }
        }
    }

    @Override
    public void set(Circuit circuit, Component comp, Attribute<?> attr,
            Object newValue) {
        if (circuit.contains(comp)) {
            modified.add(circuit);
            @SuppressWarnings("unchecked")
            Attribute<Object> a = (Attribute<Object>) attr;
            AttributeSet attrs = comp.getAttributeSet();
            Object oldValue = attrs.getValue(a);
            log.add(CircuitChange.set(circuit, comp, attr, oldValue, newValue));
            attrs.setValue(a, newValue);
        }
    }

    @Override
    public void setForCircuit(Circuit circuit, Attribute<?> attr,
            Object newValue) {
        @SuppressWarnings("unchecked")
        Attribute<Object> a = (Attribute<Object>) attr;
        AttributeSet attrs = circuit.getStaticAttributes();
        Object oldValue = attrs.getValue(a);
        log.add(CircuitChange.setForCircuit(circuit, attr, oldValue, newValue));
        attrs.setValue(a, newValue);
    }

    private ReplacementMap getMap(Circuit circuit) {
        ReplacementMap ret = replacements.get(circuit);
        if (ret == null) {
            ret = new ReplacementMap();
            replacements.put(circuit, ret);
        }
        return ret;
    }

    CircuitTransaction getReverseTransaction() {
        CircuitMutation ret = new CircuitMutation();
        ArrayList<CircuitChange> log = this.log;
        for (int i = log.size() - 1; i >= 0; i--) {
            ret.change(log.get(i).getReverseChange());
        }
        return ret;
    }

    ReplacementMap getReplacementMap(Circuit circuit) {
        return replacements.get(circuit);
    }

    void markModified(Circuit circuit) {
        modified.add(circuit);
    }

    Collection<Circuit> getModifiedCircuits() {
        return Collections.unmodifiableSet(modified);
    }
}
